Twiggy, you and I think heatmister mentioned cronic back pain. Be very carefull, this may indeed be just back pain, but then again it can be something else.
I had pain in my back for 4 months, went to 8 doctors. They told me nothing was wrong and to a man put me on tranquillizers. The parmacy in my home town knew me very well and told me I did not fit the profile for them. I used to soak in a hot tub for my back. I was working midnight shift and going to school in the daytime. One night at work, I felt like I had been kicked in the stomach, I had never had pain in the stomach before, no throwing up. My boss thought I just wanted off work, but by morning I was in shock. At the hospital they did an exploratory and I had a hole in my stomach the doctor could put his thumb in and the contents of my stomach had spilled into my gut. The pain was 'referred pain' by the vegus nerve. the stomach connects to the vegus nerve and it connects to the spine and brain. Thus referred pain. Never take pain lightly, it is the bodys way of warning, something is wrong.